Radio-frequency veneer dryer

Abstract

A continuous radio frequency dryer that includes a dryer housing and a conveyor extending through the housing. The conveyor is made up of a series of conveyor rolls spaced from each other, and a pressure roll is above and parallel to each conveyor roll. Plural sets of electrodes alternate with the conveyor rolls, and the electrodes are supplied radio frequency energy. Air is circulated through the housing.

It is claimed and desired to secure by letters patent: 
     
       1. A continuous radio-frequency veneer dryer comprising: a dryer housing,   multiple pairs of rolls within the housing defining a path of travel for veneer through the dryer, the pairs being spaced at intervals along said path of travel and the rolls of each pair extending transversely of the path of travel and including a lower conveyor roll and an upper pressure roll with the conveyor and pressure rolls engaging bottom and top faces of veneer being transported,   plural elongate electrodes distributed at spaced intervals along said path of travel within said housing and extending transversely of said path of travel,   a radio-frequency generating means having a pair of terminals energized with opposite polarity signals and conducting means connecting one of said pair of terminals to certain electrodes and the other of said pair of terminals to other of said electrodes so that electrodes of opposite polarity follow one another along said path of travel, and   means for circulating heated air against opposite faces of veneer transported by said multiple pairs of rolls.   
     
     
       2. The radio-frequency dryer of claim 1, wherein a pressure roll is yieldably biased downwardly toward the conveyor roll therebeneath. 
     
     
       3. The dryer of claim 2, wherein the conveyor and pressure rolls are aluminum-surfaced, and which includes non-conductive means mounting the conveyor and pressure rolls in the dryer housing. 
     
     
       4. The dryer of claim 1, wherein the means for circulating air comprises plural air nozzles directing heated air against faces of veneers. 
     
     
       5. A continuous radio-frequency veneer dryer comprising: a dryer housing,   a series of conveyor rolls mounted at spaced intervals within the housing and defining a path of travel for veneer through the dryer,   plural sets of rod electrodes, said sets of electrodes alternating with said conveyor rolls along the length of the dryer, each set of electrodes comprising an upper and a lower electrode disposed on opposite sides, respectively, of the path of travel of veneer,   a radio-frequency generating means having a pair of terminals energized with opposite polarity signals, and   conductor means connecting one of said pair of terminals to some of said sets of rod electrodes and the other of said pair of terminals to other of said sets of rod electrodes and the sets of electrodes connected to said one terminal alternating with sets of rod electrodes connected to said other terminal extending in the direction of travel of veneer through the dryer.   
     
     
       6. The radio-frequency dryer of claim 5, wherein a pressure roll is provided disposed above and opposite and parallelling selected ones of said conveyor rolls, and the pressure roll is yieldably biased downwardly toward the conveyor roll therebeneath. 
     
     
       7. The dryer of claim 6, wherein the conveyor and pressure rolls are aluminum-surfaced, and which further includes non-conductive means mounting the conveyor and pressure rolls in the dryer. 
     
     
       8. The dryer of claim 5, which further comprises means for circulating air against faces of veneer transported by the conveyor rolls, and wherein the means for circulating air comprises plural air nozzles directing heated air against faces of the veneers.